Improvement in electric-signaling apparatus for railroads



W. ROiBiNSON:

Improvement in Electric Signaling Apparatus for Raiiroads.

N0. 130,661. 'Pa'tenied Aug 20,1872.

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Wifiwases.

UNITED STATES PATENT Orrron WILLIAM ROBINSON, 0F BROOKLYN, NEW YORK.

IMPROVEMENT IN ELECTRIC-SIGNALING APPARATUS FOR RAILROADS.

Specification forming part ofLetters Patent No. 130,661, dated August20, 1872.

signal-box with its face removed to show the' signal within, the wholebeing arranged to illustrate my invention.

The object of this invention is to operate electric signals, audible orvisible, by means of moving or standing vehicles or trains without theuse of ordinary track-connections for .closing or breaking circuits, andwithout the use or with a limited use of line-wires for conducting theelectric current, the rails of the track beingused for the latterpurpose. The invention consists in an improved signal of very simpleconstruction, by which great ease of action is secured. It also embracescertain peculiarities in the arrangement of wires from thesign'al andbattery to the track.

A in the drawing represents a double-track railroad. G is a section oftrack, which may be a mile long, more or less, and having its rails a bseparated from metallic contact with the rails of the sections D and E,as shown at a, b. In like manner the section 0 of' the other track hasits rails separated from metallic contact with the rails of the sectionsD and E. The rails a b c (1 should each have metallic continuitythroughout the length of its section. The signal-box F is constructed ofany suitable material, and is providedwith an orifice, preferably in.the center, covered with glass windows capable of illumination, throughwhich the signal may be seen when exposed, day or night. W'ithin thissignalbox is placed the signal G, consisting of a disk, S, attached tothe lever e, which, pivoted at f, turns on a horizontal axis. To thelever 0 or its arbor is fixed the small projection or lever, preferablysegmental, g. A cord, link, chain, or delicate elastic spring, 93, isattached to the lever g and to the upper part of the long lever L, insuch a manner that when the armature m, which is attached to the leverL, is attracted by its magnet M and the upper part of said lever Lswings in the direction of the arrow 2, the upper part of the segmentallever g moves forward and downward, thus permitting the chain c to workcloser to the pivot f. By this arrangement it will be seen that thegreatest leverage-power is secured for moving the signal when thearmature m is the greatest distance from its magnet and the magneticforce is consequently weakest, the leverage-power diminishing graduallyas the armature approaches the magnet. The vertical lever L moves on ahorizontal axis, f, and is prevented from swinging too far. back fromthe magnet by the adjustable steps, which may be so adjusted as to bringthe armature m a greater or less distance from its magnet M, as may befound necessary. The levers L and away he made of any suitable materialand in any manner; but are preferably constructed of thin tubular metalfor the purpose of securing great strength and rigidity with minumumweight and friction of parts. Furthermore, the disk S is counterbalancedby an adjustable weight, w, and by making that part of the lever cembraced between the pivot f and the disk S of considerable length, thedisk S is brought from a state of concealment to a state of exposure, orthe reverse, by passing through a comparatively small angle, and byarranging the disk-lever e, as shown in the drawing, in such a mannerthat in bringing the disk from a state of concealment to a state ofexposure or the reverse, said lever 6 shall swing to and beyondahorizontal position, the greatest uniformity of motion with the leastpossible loss of power are secured.

Having thus described the construction of the visual signal G, it willbe seen that when the electro-magnet M is charged it attracts thearmature m to itself, thus swinging the upper end of the lever L in thedirection of the arrow 2, and carrying the upper end of the lever 9forward, at the same time turning the same together with the lever e onthe axis f, and carrying the disk S down into the position indicated indotted outline. Now connect one pole of the battery B withthe rails aand c, and the other pole with the rails b and d of the sections 0 and Cby means of the wires k and K", respectively. In like manner connect theends of the coils of the magnet M, the one end with the rails a and cand the other end with the rails 11 and d of the same sections 0 and Cby the wires l and l, as shown in the drawing, and the apparatus isoperative. the signal to the track are preferably insulated.

Before describing the operation of the apparatus as a whole, it may bestated that the electric current will follow a naked metallicconductorif of sufficient surface, even when immersed in a river or inthe mud at the bottom of a river, because the metal offers lessresistance to its passage than either water or mud. Much more will itfollow the rails of a railroad track when they are made a part of thecircuit, since the rails present a large sur face of good conductingmaterial, which offers much less resistance to its passage than anysurrounding mediums; and it is well known that when several courses arepresented the electric current will follow that course which oli'ersleast resistance to its passage. 7

The mode of operation is as follows: Suppose the sections 0 and G to beentirely clear of cars; then the electric current from the positive poleP of the battery B will pass as indicated by the arrows'a: :0, throughthe wire k, railb,wire l, and magnetM, chargingthe same, and returnthrough the wire I, rail a, and wire k, as indicated by the arrows y y,to the negative pole N of the battery. The magnet M, being thus charged,attracts its armature and swings the signal-disk S into the position ofconcealment shownjn dotted outline, and holds it in that position aslong as the sections 0 G are clear. Nowlet a train enter uponO or G, asindicated at H O, and the wheels and axles of the same will bridge overthe rails c and d, and thus, by ofi'ering a large conducting-surface,will present to the' electric current a complete circuit, which ofl'ersmuch less resistance to its passage than that through the magnet M. Theelectricity now takes the course over the wire 7., rail (1, wheels andaxle H, returnin g, by the rail 0 and wire k, to the battery, asindicated by the arrows a; w y, using the rails 0 and d, as will beseen, with their bridge, and

entirely avoiding the magnet M, which, beingthus demagnetized, lets goits armature, and the counterpoise 10, which slightly overbalances thedisk S, carries the same up in front of the orifice, into aposit-ion ofexposure, where it remains, as shown, while a train is on section 0 orC. When, however, the train has run oft, leaving sections (1 and 0clear, the magnet M is instantly charged again and the signal-disk S isremoved and kept concealed until the track is again blocked by thepresence of another train, when the same process is repeated. When thesignal disk is in a position of exposure, as shown, the lever l mayserve to close an additional circuit through the battery B, which may beused to operate an alarm, I, in conjunction with the signal S, or toactuate another signal at a distant point. Furthermore, the concealmentof the signal S The wires from the battery and may serve to closeanother circuit for cxposin g another signal, or the reverse. Instead ofusin g the signal G, constructed as herein min utely described, a signalof any suitable construction may be used without affecting the spirit ofthe invention. Furthermore, instead of using the magnet M to actuate thesignal directly, it it may be used as a relay, operating, when charged,to keep the circuit which directly actuates the signal open or closed,as desired. It is evident that an alarm may be used either inconjunction with or independently of a visual signal. The drawing showsan application particularly adapted to road-crossing signals on a doubletrack. The signals may be used, also, on a single track and be appliedas block-Sig nals and for other purposes on single or double tracks.When used as a block-signal or for other purposes, it may be desirableto indicate at a distant station when the signal is operative. Toaccomplish this object, carry one of the wires from the magnet M to thedistant station. Here let the wire be passed through the coils of abell-magnet or other signaling device, and thence be carried to thetrack and attachedto the same, as already described. Theofiice signalwill operate simultaneously with the signal S. Thus any desired numberof signals may be operated simultaneously, at different points, from asingle s ction of track. 1 ya slight modification of the plan describedtin eflicient switch and drawbridge signal may be operated, the railsbeing used as conductors. Thus half a mile, more or less, from a switchmaybe placed a signal-bt'ix and signal, substantially as described, andconnected with the rails, as shown. Near this point let the rails bedivided, taking care that the signal and battery wire are connected tothe section toward the switch. Now, while the switch is on the mainline, the bars connecting the rails of the switch will act as'a bridgeto divert the electricity from the signal-magnet. But when the switch ismisplaced the metallic connection of the rails of the track will beinterrupted. The signal-magnet will thus become charged and the positionof the signal changed. In this case the signal should be exposed whenthe magnet M is charged. In like manner a cross-bar may bridge the railson a draw-bridge. The displacing of the draw-bridge or withdrawing ofthe bolt or bolts which hold the same in position will allow thesignal-magnet to become charged and the signal to be changed,substantia-ll y as described, in connection with a switch. It is notnecessary in all cases that the rails a and 1), section 0, should bothbe separated from metallic contact with the sections D and .E. It mayoften, it not always, be sufficient to separate only one of said railsfrom such-metallic contact with the adjacent sections.

What I here claim as new, and desire to secure by Letters Patent, is-

1. The batteryB and magnet M, so connected with the rails of a sectionof railroad track that when said section is bridged by the wheels andaxle of a car the electric circuit is changed and the signal operatedthrough the demagnetization of the magnet M, substantially as specitied.

2. A signal constructed partially of tubular material, for the purposeof securing lightness combined with strength, in the mannersubstantially as herein set forth;

3. The arrangement of the pivotal bearing of the lever e at a pointmidway between the horizontal lines of exposure and concealment of thesignal-disk, as shown and described,for the purpose set forth.

4. The combination of the elastic spring i, or

